I bought a demo Sidewinder this season. It had 2100 kms on it and was one of Yamahas corporate demo sled. The sled had some remnants of blown belts. How many belts, who knows.
I noticed this when I picked the sled up, and I asked the dealership to clean the clutches, and inspect them for any issues because i didnt want a belt blowing POS.
When I installed my clutch weights, I noticed 2 of the primary bushings didnt roll properly. I took them off and discovered the bushings werent pressed into the roller enough, causing the busing to drag on the washers, making the roller hard to spin. This sled must have been like this from the factory, and could be why it was blowing belts. The secondary rollers were also slightly flatspotted. You couldnt tell they were flatspotted unless you took the helix off.
Theres seems to be a lot of small assembly issues with these sleds. The rollers not being proper on my clutch, boost and bov lines not routed correctly, loose clamps, etc